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A fun, free platform for learning modern cryptography

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Learn By Doing

Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.

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Level Up

Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?

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Fresh Challenges

We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.

New Challenges
RSA or HMAC? Part 2 Crypto on the Web 100
Roll your Own Mathematics 90
Dancing Queen Symmetric Ciphers 120
SSH Keys General 35
LFSR Destroyer Misc 250
Weekly Top Users
#1 someone12469 3100
#2 fsh 2450
#3 Cib 2145
#4 crawfish 1970
#5 zeski 1820
Recent Solves
Base64 Echo_Slow
Encoding Challenge Shaharino
Greatest Common Divisor TheMorningStar
You either know, XOR you don't TheMorningStar
Salty pturtle
Recent Solutions
Broken RSA Hamilton 0
Bean Counter Hamilton 0
Montgomery's Ladder mathno1 0
Greatest Common Divisor mmgordon82 0
Jack's Birthday Confusion Hamilton 0

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